Adding test case to verify #248 - zero password login

This test verifies that it is possible to exploit the authentication adapter of DoctrineModule to
login into a system if the password is zero, empty or casted to zero.
Applying fix for #248

As suggested by @bakura10, this fix removes the security hole by preventing automatic type casting from affecting authentication via zero password
Merge branch 'hotfix/issue-#248-zero-password-login' - fixes #248 - diallows zero-password-login
Add isser to extract by value
Adding test that verifies #227 - criteria is ignored in `count`
Applying fix for #227 - verifies that the criteria object is used in `count`

Fixes #227
Merge pull request #251 from doctrine/hotfix/issue-#227-selectable-adapter-count

Adding test that verifies #227 - criteria is ignored in `count`
Add test
Merge pull request #250 from bakura10/patch-1

Add isser to extract by value